1. Field of the Invention
The invention relates to the field of static structures. More particularly, the invention relates to insulation modules attachable to a static structure. In still greater particularity, the invention is a method and apparatus for fastening an insulation module to the interior surface of a furnace. By way of further characterization, but not by way of limitation thereto, the invention includes a threaded stud welded to the surface with the insulation module threadably secured to the stud.
2. Description of the Related Art
Many methods in apparatus exist for attaching insulation modules to the inside of furnaces and the like. Previously, the insulation modules were attached by utilizing exterior hardware. That is, hangers or the like were employed and the insulating material was impaled thereon. Such a system is shown in U.S. Pat. No. 3,892,396. The use of hangers with individual insulating layers suffer from the disadvantage that each individual layer be placed on the hangers which is a time consuming process. In addition, the support provided by the hangers is less than desirable and the layers may tear away under stress. For these reasons, most insulation today is in the form of a prefabricated module which is attached to the furnace lining as opposed to individual layers.
Other systems, such as that shown in U.S. Pat. No. 3,523,395 employ members which are attached to the furnace lining with the insulating material impaled thereon. An exterior fastener, is then pushed into the insulating material and attached to the member which is secured to the wall of the furnace. While suited for their intended purposes, the above apparatus suffer from certain deficiencies in addition to those listed above. That is, if the supporting hardware is exposed to the interior of the furnace, heat from the furnace could cause failure of the hardware resulting in separation of the insulating material from the furnace lining.
The attachment of insulation modules to a furnace lining has been accomplished by attaching a stud or other member to the insulation module. The stud is passed through the wall of the furnace and secured from the outside of the furnace. While suited for its intended purpose, such an attachment means is not suited for all applications. In some situations it is desirable to have an attachment means to the inside of the furnace wall. In such situations, the welding or other attachment of the fastening means to the interior of the furnace wall is desirable. One such system, herein refered to as the "blind weld system", utilizes a stud welding gun which is inserted through the insulation module and held against the furnace wall. That is, the welding of the stud to the furnace wall is done through the insulation module with a nut or other fastening means then used to attach the module to the stud. One major disadvantage of such a system is that the stud must be welded to the furnace wall without visual observation by the welder. Thus, faulty or improper welds cannot be observed. The result is that failures can occur which result in the insulation modules being separated from the furnace wall.